The basic design of a cover for a spa or hot tub (collectively referred to in this disclosure as a "spa") is well known in the art. The design essentially comprises a single piece or several pieces of rigid material, typically a thermally insulating material, encased in a water-resistant sheet material. The rigid material is shaped to cover the top opening of a particular design of spa. Handles are attached to the encasing sheet material to aid removal of the cover, and securing tabs are similarly attached to secure the cover onto the top opening of the spa.
A spa cover of this basic design performs several functions. The cover reduces loss of heat from the water in the spa. The cover prevents entry of debris into the spa. The cover prevents accidental injury of small children and others who might fall into the spa. Because spas are often located outside any protective structure, the cover also prevents the entry of natural elements such as rain, snow, sleet and hail into the spa. The present invention performs all these functions.
In typical previous designs at least six separate pieces of sheet material are required to encase the rigid material: top, bottom, side and end gussets, flaps, handles, and tabs. Often the gussets and flaps are produced from scrap material and so may be comprised of a plurality of even smaller pieces of sheet material. In previous designs these pieces of sheet material are sewn together inside out and then turned right side out to form the encasement.
Previous designs of a spa cover encasement formed by a plurality of sheet material pieces sewn together have proved unsatisfactory. When exposed to natural elements over a period of time the sewn seams inevitably allow moisture to penetrate inside the spa cover. This results in the formation of mold and mildew in the spa cover.
Construction of such a spa cover encasement may take an unacceptably long time because of the presence of a plurality of seams which must be sewn. A reduction in the time of construction, a labor intensive activity, will significantly reduce the cost of the completed spa covers.